Rubyzip 1.0

Our build scripts that use albacore use other gems as well and some of them depend on rubyzip 1.0.0. This change is to make it so albacore will work with rubyzip 1.0.0

I know you're getting ready to release albacore 1.0.0, I think this would be a great change to get into that release since you're already going up a major version and then you'd be on the latest version of rubyzip as opposed to be tied to an older verison.

Also, the `zip_spec` tests weren't passing even before my change to rubyzip 1.0. So my first changeset is to make those tests pass, so I would know that my change to rubyzip 1.0 works.